Method of treating distillery waste



A. A. BACKHAUS AND C. HANER, JR. METHOD 0F TREATING DISTILLERY WASTE.

APPLICATION FILED ocT. 2z. 1911. IIENEwED IuLY I9, m9. 1,396,006.

Patented Nov. 8, 1921.

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UNITED STATES PATENT- OFFICE.

ARTHUR A. BACKHAUS AND CARL HANER, JR., OF BALTIMORE, MARYLAND, ASSIGNORS TO U. S. INDUSTRIAL ALCOHOL CO., A CORPORATION OF WEST VIRGINIA..

METHOD OF TREATING DISTILLERY WASTE.

Specification of Letters Patent.

Patented Nov. 8, 1921.

Application led October 22, 1917, Serial No. 197,885. Renewed July 19, 1919. Serial No. 312,030.

. To all whom it may concern Be it known that we, ARTHUR A. BACK- HAUs and CARL HANER, Jr., of Baltimore, in the State of Maryland, have invented a certain ,new and useful Improvement in Methods of Treating Distillery Waste, and do hereby declare that the ,following is a full, clear, and exact description thereof.

Our invention relates .particularly to a process for treating the waste or slop obtained from distilleries in the production of alcohol. Y

The object of our invention is particularly to utiliie the waste obtained from the distillation of various materials used in the production of ethyl alcohol.

More particularly, the object of our invention is to make use of the waste materials obtained in the production ofpethyl alcohol from molasses, which may, for example, be obtained in the manufacture of cane or beet sugar, or from potatoes, grain, such as wheat, rye, barley, corn, etc.

The object of our invention is, furthermore, to provide a process ofobtaining volatile organic acids, and particularly volatile acids of the aliphatic series.

Further objects of our invention will appear from the detailed description thereof contained hereinafter.

While our invention is capable of being carried out in many different ways, for the purpose of illustration, we shall describe only one way .of carrying out the same herein; and, while our invention is capable of being carried out in connection with many different types of apparatus, we shall describe only one type of apparatus which may be used in connection therewith as illustrated in the accompanying drawings, in which- Figure 1 is a diagrammatic representation of an apparatus which may be used in connection with our invention; and

Fig. 2 is an end elevation of a type of car used in connection with the same.

In the drawings, we have shown two preliminary mixing tanks 1, having a plurality of stirrer arms 2, adapted to be rotated in any suitable manner, said tanks 1 being provided lfor mixingcaustic alkali with a quantity of the magma, which is evaporated dis` tillery waste or slop, and which may have a density of 25 B. or higher.

From the mixing tanks 1, the material is conveyed into a plurailty of pans 3 onmeans i such as trucks 4', shown as containing racks 5 to receive the same, which trucks are shown as arranged to run upon a track 7 into a furnace chamber 8. The material in the vpans 3 becomes dried in 'this manner to form a clinken This clinker contains sodium oxalate, aswell assodium salts of a number of volatile acids, such as formic, acetic, butyric acids, etc. The clinker is then removed from the pans and introduced into a plurality of wooden tanks 9. These tanks 9 are supplied with a quantity of water and sulfuric acid, and the contents of said tanks are adapted to be heated by means of live steam fed into the same by means of a pipe 10, having branch pipes 11, leading into the same. Said steam pipes 11 may have a pipe 12 connected thereto to supply compressed air, in order to assist in the agitation of the materials contained in' the tanks. The lsulfuric acid is added to neutralize the excess alkali as this neutralization is found to aid in the subsequent filtration. Thereafter a quanity iof lime is added suflicient to precipitate the oxalic acid as calcium oxalate. The liquids are then transferred vfrom the tanks 9 to a filter 13. The filtrate from the filter 13, which contains the sodium salts of l which is provided with an outlet pipe 21,

leading to two receiving tanks 22 and 23,

connected by a pipe 24 to a vacuum pump.

The volatile acids collect in the tanks 22 and 23 and may be withdrawn therefrom for use in any desired manner or for separation, as

may be desired.

As a specific example of our invention, we may proceed as follows: A quantity of the distillery waste or slop, after having had the alcohol removed therefrom, is evaporated inthe usual way to form a magma, which may have a density of 25 B. or higher. This magma may be mixed in the proportlon of three parts by weight of magma to one part by weight of caustic soda in the tanks 2,

until the alkali has become completely dis-7,

solved. If desired, the two tanks 2 may be operated'alternately, so that, While one tank is being charged, the other is being discharged. The mixture thus obtained is transferred to the pans 3 on the trucks 4 and is introduced into the furnace chamber 8, Where the material is subjected to a temperature of from 175O to 250 C. for 8 to 24 hours, the time of treatment being varied according to the temperature. Where the temperature is low, the treatment is for a longer period of time than Where the temperature is higher. When the reaction is complete,-the treatment in the furnace chamber 8 is discontinued. The effect of the treatment in the furnace chamber 8 is principally to bring about the production of volatile organic acids as Well as oxalic acid. The clinker thus obtained, and which contains a quantity of sodium oxalate amounting to approximately 10% of the Weight of the clinker and a quantity of sodium salts of a number of volatile acids, such as formic, acetic, butyric acids, etc., amounting to from 12% to 20% of the Weight of the clinker, is treated with sulfuric acid in the proportions of one part by Weight of clinker, two parts by weight of Water, and one-third part by Weight of sulfuric acid of 66 B. in the tanks 9. The amount of sulfuric acid that is used is sufficient merely to neutralize the alkaliand not to liberate the oXalic acid and volatile acids from their sodium salts. During the treatment With the sulfuric acid, heat is applied by the injection of live steam through the pipe 10, together with compressed air through the pipe 12, if desired. Then a sufficient quantity of lime is added to precipitate the oxalic acid as calcium oxalate. The amount of lime added will usually'be about 5% of the Weight of the clinker introduced into the tanks 9. The calcium oxalate and other solid materials present are then se arated from the liquids by means of the lter 13. The filtrate from this filter will contain the sodium salts of the volatile vacids above referred to.

The filtrate is'then evaporated to dryness, or nearly so. The Vsolid materials are then introduced into still Hand treated with sufficient sulfuric acid of 66 B. to liberate the volatile acids from their salts. For example,

one part of sulfuric acid of 66 B. may be added to four parts of the solids in the still. The volatile acids are then distilled over and condensed together with some water in the condenser 20, and the distillate is finally collected in the receivers 22 and 23, whence they can be removed for any desired purpose, or for separation, as desired.

While We have described our invention above in detail, we wish it to be understood that many changes may be made therein Without departing from the spirit of our invention. For example, instead of calcium compounds, We may use salts of the other alkaline earth metals, andV We Wish this .to be understood Wherever We have referred t0 the use of calcium compounds, and instead of caustic soda, We may use other alkalis or carbonates of the alkali metals or mixtures of the same.

We claim:

l. The process of treating distillery slop comprising concentrating it, adding caustic soda, heating at a temperature from 175 to 250o C., adding lime to form calcium oxalate, filtering, evaporating the filtrate to dryness, and distilling With sulfuricacid to recover volatile acids.

2. The process ofl treating distillery slop comprising concentrating it to about 25 B., adding caustic soda in the proportion of one part soda to one part magma, heating at a temperature of 175 to 250 C., neutralizing the alkali with an acid, adding lime to form calcium oxalate, filtering, evaporating the filtrate to dryness, and distilling the sulfuric acid to recover volatile acids.

3. T he process of treating distillery slop comprising concentrating it, adding an alkali, heating at a temperature of from 175 to 250 C., adding a calcium compound to form calcium oXalate, filtering, evaporating the filtrate to dryness, and distilling with a relatively less volatile acid to recover the volatile4 acids of the distillery slop.

In testimony that We claim the foregoing We have hereunto set our hands.

ARTHUR A. BACKHAUS.

Y CARL HANER, J R.

Witnesses:

DEzs E. KELEN, I. D. WHEAgoN. 

